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ASoC: omap-pcm: Convert to use dmaengine
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Original author: Russell King <rmk+kernel@arm.linux.org.uk>

Switch the omap-pcm to use dmaengine.
Certain features are not supported by after dmaengine conversion:
1. No period wakeup mode
   DMA engine has no way to communicate this information through
   standard channels.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
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Peter Ujfalusi authored and Mark Brown committed Sep 22, 2012
1 parent bcd6da7 commit 946cc36
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Showing 2 changed files with 61 additions and 211 deletions.
3 changes: 2 additions & 1 deletion sound/soc/omap/Kconfig
View file
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
config SND_OMAP_SOC
tristate "SoC Audio for the Texas Instruments OMAP chips"
depends on ARCH_OMAP
depends on ARCH_OMAP && DMA_OMAP
select SND_SOC_DMAENGINE_PCM

config SND_OMAP_SOC_DMIC
tristate
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269 changes: 59 additions & 210 deletions sound/soc/omap/omap-pcm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -25,12 +25,13 @@
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/omap-dma.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/dmaengine_pcm.h>
#include <sound/soc.h>

#include <plat/dma.h>
#include "omap-pcm.h"

static const struct snd_pcm_hardware omap_pcm_hardware = {
Expand All @@ -49,61 +50,34 @@ static const struct snd_pcm_hardware omap_pcm_hardware = {
.buffer_bytes_max = 128 * 1024,
};

struct omap_runtime_data {
spinlock_t lock;
struct omap_pcm_dma_data *dma_data;
int dma_ch;
int period_index;
};

static void omap_pcm_dma_irq(int ch, u16 stat, void *data)
static int omap_pcm_get_dma_buswidth(int num_bits)
{
struct snd_pcm_substream *substream = data;
struct snd_pcm_runtime *runtime = substream->runtime;
struct omap_runtime_data *prtd = runtime->private_data;
unsigned long flags;

if ((cpu_is_omap1510())) {
/*
* OMAP1510 doesn't fully support DMA progress counter
* and there is no software emulation implemented yet,
* so have to maintain our own progress counters
* that can be used by omap_pcm_pointer() instead.
*/
spin_lock_irqsave(&prtd->lock, flags);
if ((stat == OMAP_DMA_LAST_IRQ) &&
(prtd->period_index == runtime->periods - 1)) {
/* we are in sync, do nothing */
spin_unlock_irqrestore(&prtd->lock, flags);
return;
}
if (prtd->period_index >= 0) {
if (stat & OMAP_DMA_BLOCK_IRQ) {
/* end of buffer reached, loop back */
prtd->period_index = 0;
} else if (stat & OMAP_DMA_LAST_IRQ) {
/* update the counter for the last period */
prtd->period_index = runtime->periods - 1;
} else if (++prtd->period_index >= runtime->periods) {
/* end of buffer missed? loop back */
prtd->period_index = 0;
}
}
spin_unlock_irqrestore(&prtd->lock, flags);
}
int buswidth;

snd_pcm_period_elapsed(substream);
switch (num_bits) {
case 16:
buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
break;
case 32:
buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
break;
default:
buswidth = -EINVAL;
break;
}
return buswidth;
}


/* this may get called several times by oss emulation */
static int omap_pcm_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct omap_runtime_data *prtd = runtime->private_data;
struct omap_pcm_dma_data *dma_data;

struct dma_slave_config config;
struct dma_chan *chan;
int err = 0;

dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
Expand All @@ -116,203 +90,87 @@ static int omap_pcm_hw_params(struct snd_pcm_substream *substream,
snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
runtime->dma_bytes = params_buffer_bytes(params);

if (prtd->dma_data)
return 0;
prtd->dma_data = dma_data;
err = omap_request_dma(dma_data->dma_req, dma_data->name,
omap_pcm_dma_irq, substream, &prtd->dma_ch);
if (!err) {
/*
* Link channel with itself so DMA doesn't need any
* reprogramming while looping the buffer
*/
omap_dma_link_lch(prtd->dma_ch, prtd->dma_ch);
}

return err;
}

static int omap_pcm_hw_free(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct omap_runtime_data *prtd = runtime->private_data;

if (prtd->dma_data == NULL)
return 0;
chan = snd_dmaengine_pcm_get_chan(substream);
if (!chan)
return -EINVAL;

omap_dma_unlink_lch(prtd->dma_ch, prtd->dma_ch);
omap_free_dma(prtd->dma_ch);
prtd->dma_data = NULL;
/* fills in addr_width and direction */
err = snd_hwparams_to_dma_slave_config(substream, params, &config);
if (err)
return err;

snd_pcm_set_runtime_buffer(substream, NULL);
/* Override the *_dma addr_width if requested by the DAI driver */
if (dma_data->data_type) {
int buswidth = omap_pcm_get_dma_buswidth(dma_data->data_type);

return 0;
}
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
config.dst_addr_width = buswidth;
else
config.src_addr_width = buswidth;
}

static int omap_pcm_get_dma_type(int num_bits)
{
int data_type;
config.src_addr = dma_data->port_addr;
config.dst_addr = dma_data->port_addr;
config.src_maxburst = dma_data->packet_size;
config.dst_maxburst = dma_data->packet_size;

switch (num_bits) {
case 16:
data_type = OMAP_DMA_DATA_TYPE_S16;
break;
case 32:
data_type = OMAP_DMA_DATA_TYPE_S32;
break;
default:
data_type = -EINVAL;
break;
}
return data_type;
return dmaengine_slave_config(chan, &config);
}

static int omap_pcm_prepare(struct snd_pcm_substream *substream)
static int omap_pcm_hw_free(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct omap_runtime_data *prtd = runtime->private_data;
struct omap_pcm_dma_data *dma_data = prtd->dma_data;
struct omap_dma_channel_params dma_params;
int bytes;

/* return if this is a bufferless transfer e.g.
* codec <--> BT codec or GSM modem -- lg FIXME */
if (!prtd->dma_data)
return 0;

memset(&dma_params, 0, sizeof(dma_params));

if (dma_data->data_type)
dma_params.data_type = omap_pcm_get_dma_type(
dma_data->data_type);
else
dma_params.data_type = omap_pcm_get_dma_type(
snd_pcm_format_physical_width(runtime->format));

if (dma_params.data_type < 0)
return dma_params.data_type;

dma_params.trigger = dma_data->dma_req;

if (dma_data->packet_size)
dma_params.sync_mode = OMAP_DMA_SYNC_PACKET;
else
dma_params.sync_mode = OMAP_DMA_SYNC_ELEMENT;

if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
dma_params.src_amode = OMAP_DMA_AMODE_POST_INC;
dma_params.dst_amode = OMAP_DMA_AMODE_CONSTANT;
dma_params.src_or_dst_synch = OMAP_DMA_DST_SYNC;
dma_params.src_start = runtime->dma_addr;
dma_params.dst_start = dma_data->port_addr;
dma_params.dst_port = OMAP_DMA_PORT_MPUI;
dma_params.dst_fi = dma_data->packet_size;
} else {
dma_params.src_amode = OMAP_DMA_AMODE_CONSTANT;
dma_params.dst_amode = OMAP_DMA_AMODE_POST_INC;
dma_params.src_or_dst_synch = OMAP_DMA_SRC_SYNC;
dma_params.src_start = dma_data->port_addr;
dma_params.dst_start = runtime->dma_addr;
dma_params.src_port = OMAP_DMA_PORT_MPUI;
dma_params.src_fi = dma_data->packet_size;
}
/*
* Set DMA transfer frame size equal to ALSA period size and frame
* count as no. of ALSA periods. Then with DMA frame interrupt enabled,
* we can transfer the whole ALSA buffer with single DMA transfer but
* still can get an interrupt at each period bounary
*/
bytes = snd_pcm_lib_period_bytes(substream);
dma_params.elem_count = bytes >> dma_params.data_type;
dma_params.frame_count = runtime->periods;
omap_set_dma_params(prtd->dma_ch, &dma_params);

if ((cpu_is_omap1510()))
omap_enable_dma_irq(prtd->dma_ch, OMAP_DMA_FRAME_IRQ |
OMAP_DMA_LAST_IRQ | OMAP_DMA_BLOCK_IRQ);
else if (!substream->runtime->no_period_wakeup)
omap_enable_dma_irq(prtd->dma_ch, OMAP_DMA_FRAME_IRQ);
else {
/*
* No period wakeup:
* we need to disable BLOCK_IRQ, which is enabled by the omap
* dma core at request dma time.
*/
omap_disable_dma_irq(prtd->dma_ch, OMAP_DMA_BLOCK_IRQ);
}

if (!(cpu_class_is_omap1())) {
omap_set_dma_src_burst_mode(prtd->dma_ch,
OMAP_DMA_DATA_BURST_16);
omap_set_dma_dest_burst_mode(prtd->dma_ch,
OMAP_DMA_DATA_BURST_16);
}

snd_pcm_set_runtime_buffer(substream, NULL);
return 0;
}

static int omap_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct omap_runtime_data *prtd = runtime->private_data;
struct omap_pcm_dma_data *dma_data = prtd->dma_data;
unsigned long flags;
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct omap_pcm_dma_data *dma_data;
int ret = 0;

spin_lock_irqsave(&prtd->lock, flags);
dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_RESUME:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
prtd->period_index = 0;
/* Configure McBSP internal buffer usage */
if (dma_data->set_threshold)
dma_data->set_threshold(substream);

omap_start_dma(prtd->dma_ch);
break;

case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_SUSPEND:
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
prtd->period_index = -1;
omap_stop_dma(prtd->dma_ch);
break;
default:
ret = -EINVAL;
}
spin_unlock_irqrestore(&prtd->lock, flags);

if (ret == 0)
ret = snd_dmaengine_pcm_trigger(substream, cmd);

return ret;
}

static snd_pcm_uframes_t omap_pcm_pointer(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct omap_runtime_data *prtd = runtime->private_data;
dma_addr_t ptr;
snd_pcm_uframes_t offset;

if (cpu_is_omap1510()) {
offset = prtd->period_index * runtime->period_size;
} else if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
ptr = omap_get_dma_dst_pos(prtd->dma_ch);
offset = bytes_to_frames(runtime, ptr - runtime->dma_addr);
} else {
ptr = omap_get_dma_src_pos(prtd->dma_ch);
offset = bytes_to_frames(runtime, ptr - runtime->dma_addr);
}

if (offset >= runtime->buffer_size)
offset = 0;
if (cpu_is_omap1510())
offset = snd_dmaengine_pcm_pointer_no_residue(substream);
else
offset = snd_dmaengine_pcm_pointer(substream);

return offset;
}

static int omap_pcm_open(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct omap_runtime_data *prtd;
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct omap_pcm_dma_data *dma_data;
int ret;

snd_soc_set_runtime_hwparams(substream, &omap_pcm_hardware);
Expand All @@ -321,25 +179,17 @@ static int omap_pcm_open(struct snd_pcm_substream *substream)
ret = snd_pcm_hw_constraint_integer(runtime,
SNDRV_PCM_HW_PARAM_PERIODS);
if (ret < 0)
goto out;

prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
if (prtd == NULL) {
ret = -ENOMEM;
goto out;
}
spin_lock_init(&prtd->lock);
runtime->private_data = prtd;
return ret;

out:
dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
ret = snd_dmaengine_pcm_open(substream, omap_dma_filter_fn,
&dma_data->dma_req);
return ret;
}

static int omap_pcm_close(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;

kfree(runtime->private_data);
snd_dmaengine_pcm_close(substream);
return 0;
}

Expand All @@ -360,7 +210,6 @@ static struct snd_pcm_ops omap_pcm_ops = {
.ioctl = snd_pcm_lib_ioctl,
.hw_params = omap_pcm_hw_params,
.hw_free = omap_pcm_hw_free,
.prepare = omap_pcm_prepare,
.trigger = omap_pcm_trigger,
.pointer = omap_pcm_pointer,
.mmap = omap_pcm_mmap,
Expand Down

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